Anatomy of a Song (1976) is a half hour documentary (part two here) about Stephen Sondheim's song Someone in a Tree, from the musical Pacific Overtures. Sondheim talks about the challenges and thought processes behind what he calls his favourite of his own songs. See the original 1976 show in full here. Also see this earlier post on the same song.
For everyone who's thinking about assassins today, I offer up Sondheim and Weidman's take. [more inside]